2,4-Dinitrophenol

51-28-5

Hazard Summary-Created in April 1992; Revised in January 2000

2,4-Dinitrophenol is used in the manufacture of dyes, wood preservatives,
and as a pesticide. The acute (short-term) effects of 2,4-dinitrophenol
in humans through oral exposure are nausea, vomiting, sweating, dizziness,
headaches, and loss of weight. Chronic (long-term) oral exposure
to 2,4-dinitrophenol in humans has resulted in the formation of cataracts
and skin lesions, weight loss, and has caused effects on the bone marrow,
central nervous system (CNS), and cardiovascular system. Limited
or no information is available on the developmental, reproductive, or
carcinogenic effects of 2,4-dinitrophenol in humans. EPA has not
classified 2,4-dinitrophenol for carcinogenicity.

Uses

2,4-Dinitrophenol is used in the manufacture of dyes and wood preservatives,
as a pesticide, and as an indicator for the detection of potassium and
ammonium ions. (1,6)

During the 1930s, 2,4-dinitrophenol was used as a diet pill, but
this use was stopped in 1938. (1)

Sources and Potential Exposure

Exposure to 2,4-dinitrophenol occurs from pesticide runoff to water
and from releases to the air from manufacturing plants. (1)

Assessing Personal Exposure

2,4-Dinitrophenol can be measured in the blood, urine, and tissues
of exposed persons. (1)

Health Hazard Information

Acute Effects:

Acute oral exposure to high levels of 2,4-dinitrophenol in humans
has resulted in increased basal metabolic rate, nausea, vomiting, sweating,
dizziness, headache, loss of weight, and other symptoms. (1,2)

2,4-Dinitrophenol is considered to have high
acute toxicity, based on short-term animal tests in rats and mice. (3)

Chronic Effects(Noncancer):

Chronic oral exposure to 2,4-dinitrophenol in humans and animals
has resulted in the formation of cataracts and skin lesions and has
caused effects on the bone marrow, CNS, and cardiovascular system. (1,2)

The Reference Dose (RfD)
for 2,4-dinitrophenol is 0.002 milligrams per kilogram body weight per
day (mg/kg/d) based on cataract formation in humans. The RfD
is an estimate (with uncertainty spanning perhaps an order of magnitude)
of a daily oral exposure to the human population (including sensitive
subgroups), that is likely to be without appreciable risk of deleterious
noncancer effects during a lifetime. It is not a direct estimator of
risk but rather a reference point to gauge the potential effects. At
exposures increasingly greater than the RfD,
the potential for adverse health effects increases. Lifetime exposure
above the RfD does not imply
that an adverse health effect would necessarily occur. (4)

EPA has low confidence in the study on which the RfD
was based since this study only describes anecdotal data; low confidence
in the database since the supporting database is meager; and, consequently,
low confidence in the RfD.
(4)

EPA has not established a Reference Concentration (RfC)
for 2,4-dinitrophenol. (4)

Reproductive/Developmental Effects:

Case reports of women taking 2,4-dinitrophenol orally for weight
loss suggest that it may affect the female reproductive system, but
the limited information is inconclusive. (1)

One study reported an increased incidence of stillborn animals and
increased pup mortality in the offspring of animals exposed to 2,4-dintrophenol
by gavage. (1)

Cancer Risk:

No information is available on the carcinogenic effects of 2,4-dinitrophenol
in humans. (1)

One study reported that 2,4-dinitrophenol did not promote tumor development
in mice. (1,5)

EPA has not classified 2,4-dinitrophenol for potential carcinogenicity.
(4)

Physical Properties

The chemical formula for 2,4-dinitrophenol is C6H4N2O5
and the molecular weight is 184.11 g/mol. (6)

Health Data from Oral Exposure

LD50 (Lethal Dose50)--A calculated dose of
a chemical in water to which exposure for a specific length of time is expected
to cause death in 50% of a defined experimental animal population. LOAEL--Lowest-observed-adverse-effect level.

The health values cited in this factsheet were obtained in December 1999.aHealth numbers are toxicological numbers
from animal testing or risk assessment values developed by EPA. bRegulatory numbers are values that have been
incorporated in Government regulations, while advisory numbers are nonregulatory
values provided by the Government or other groups as advice. cThe LOAEL is from the critical study used
as the basis for the EPA RfD.